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-rw-r--r--arch/x86/kernel/apic/init.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/init.c b/arch/x86/kernel/apic/init.c
new file mode 100644
index 000000000..821e2e536
--- /dev/null
+++ b/arch/x86/kernel/apic/init.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define pr_fmt(fmt) "APIC: " fmt
+
+#include <asm/apic.h>
+
+#include "local.h"
+
+/*
+ * Use DEFINE_STATIC_CALL_NULL() to avoid having to provide stub functions
+ * for each callback. The callbacks are setup during boot and all except
+ * wait_icr_idle() must be initialized before usage. The IPI wrappers
+ * use static_call() and not static_call_cond() to catch any fails.
+ */
+#define DEFINE_APIC_CALL(__cb) \
+ DEFINE_STATIC_CALL_NULL(apic_call_##__cb, *apic->__cb)
+
+DEFINE_APIC_CALL(eoi);
+DEFINE_APIC_CALL(native_eoi);
+DEFINE_APIC_CALL(icr_read);
+DEFINE_APIC_CALL(icr_write);
+DEFINE_APIC_CALL(read);
+DEFINE_APIC_CALL(send_IPI);
+DEFINE_APIC_CALL(send_IPI_mask);
+DEFINE_APIC_CALL(send_IPI_mask_allbutself);
+DEFINE_APIC_CALL(send_IPI_allbutself);
+DEFINE_APIC_CALL(send_IPI_all);
+DEFINE_APIC_CALL(send_IPI_self);
+DEFINE_APIC_CALL(wait_icr_idle);
+DEFINE_APIC_CALL(wakeup_secondary_cpu);
+DEFINE_APIC_CALL(wakeup_secondary_cpu_64);
+DEFINE_APIC_CALL(write);
+
+EXPORT_STATIC_CALL_TRAMP_GPL(apic_call_send_IPI_mask);
+EXPORT_STATIC_CALL_TRAMP_GPL(apic_call_send_IPI_self);
+
+/* The container for function call overrides */
+struct apic_override __x86_apic_override __initdata;
+
+#define apply_override(__cb) \
+ if (__x86_apic_override.__cb) \
+ apic->__cb = __x86_apic_override.__cb
+
+static __init void restore_override_callbacks(void)
+{
+ apply_override(eoi);
+ apply_override(native_eoi);
+ apply_override(write);
+ apply_override(read);
+ apply_override(send_IPI);
+ apply_override(send_IPI_mask);
+ apply_override(send_IPI_mask_allbutself);
+ apply_override(send_IPI_allbutself);
+ apply_override(send_IPI_all);
+ apply_override(send_IPI_self);
+ apply_override(icr_read);
+ apply_override(icr_write);
+ apply_override(wakeup_secondary_cpu);
+ apply_override(wakeup_secondary_cpu_64);
+}
+
+#define update_call(__cb) \
+ static_call_update(apic_call_##__cb, *apic->__cb)
+
+static __init void update_static_calls(void)
+{
+ update_call(eoi);
+ update_call(native_eoi);
+ update_call(write);
+ update_call(read);
+ update_call(send_IPI);
+ update_call(send_IPI_mask);
+ update_call(send_IPI_mask_allbutself);
+ update_call(send_IPI_allbutself);
+ update_call(send_IPI_all);
+ update_call(send_IPI_self);
+ update_call(icr_read);
+ update_call(icr_write);
+ update_call(wait_icr_idle);
+ update_call(wakeup_secondary_cpu);
+ update_call(wakeup_secondary_cpu_64);
+}
+
+void __init apic_setup_apic_calls(void)
+{
+ /* Ensure that the default APIC has native_eoi populated */
+ apic->native_eoi = apic->eoi;
+ update_static_calls();
+ pr_info("Static calls initialized\n");
+}
+
+void __init apic_install_driver(struct apic *driver)
+{
+ if (apic == driver)
+ return;
+
+ apic = driver;
+
+ if (IS_ENABLED(CONFIG_X86_X2APIC) && apic->x2apic_set_max_apicid)
+ apic->max_apic_id = x2apic_max_apicid;
+
+ /* Copy the original eoi() callback as KVM/HyperV might overwrite it */
+ if (!apic->native_eoi)
+ apic->native_eoi = apic->eoi;
+
+ /* Apply any already installed callback overrides */
+ restore_override_callbacks();
+ update_static_calls();
+
+ pr_info("Switched APIC routing to: %s\n", driver->name);
+}